Measurement of Thromboxane Production in Vivo: Metabolic and Analytical Aspects

Abstract

In studies aiming at establishing a role for thromboxanes in various physiological or pathological conditions, it is often desirable to measure the endogenous thromboxane production. Since TXA2 is difficult to measure as such, a common approach in such studies is to monitor its stable hydrolysis product, TXB2, instead, and to compare obtained TXB2 levels in, for example, plasma samples in patient and control groups. Numerous such studies have been published to date; however, even the so called “basal” TXB2 levels reported therein vary widely. Not infrequently, “basal” TXB2 levels were found to be around 100–200 pg/ml plasma or even higher, however, others claim to find values below 15, 10 or even 2 pg/ml (e.g., refs. 1–6). It is difficult to explain such differences between studies where identical assay methods have been used (for example a commercially available TXB2 radioimmunoassay); that is, if the obtained data really reflect the endogenous situation.